A computer network generally includes a number of interconnected network devices. Large networks, such as the Internet, typically include a number of interconnected computer networks, which in this context are often referred to as sub-networks or subnets. These subnets are each assigned a range of network addresses that can be allocated to the individual network devices that reside in the respective subnet. A server or other device in each subnet may be responsible for allocating these network addresses in accordance with a network address allocation protocol, such as a dynamic host configuration protocol (DHCP).
Access networks often assign private network addresses to the subscriber device (e.g., cable modems, DLS modems, mobile devices) used by their customers. For example, a DHCP server or RADIUS server may dynamically assign a private address to a subscriber device upon establishing a network connection for the subscriber device. When not in use, the network connection is torn down and the private address is returned to a pool of provider addresses utilized within the access network. These private addresses may not be routable outside the access network. Instead, a network address translation (NAT) device translates the private addresses used by subscriber device to public network addresses that are routable within a public network, such as the Internet.